fix(plugin): wrap setCustomClientBuilder in BuildConfig.DEBUG guard

[imsankalp]

Summary

• Both KOTLIN_SNIPPET and JAVA_SNIPPET in plugin/src/index.js now wrap the setCustomClientBuilder call in if (BuildConfig.DEBUG) { ... }
• Idempotency check is unchanged — it still detects already-patched files correctly via NetworkToolsManager.addInterceptor(builder), which remains present inside the guard
• Tests expanded from 2 to 8 (Kotlin + Java each get: guard presence, guard ordering, idempotency, null-on-missing-onCreate)

Before vs after (Kotlin)

Before — interceptor registered unconditionally in every build:

override fun onCreate() {
    super.onCreate()

    NetworkingModule.setCustomClientBuilder(   // runs in production ❌
        object : NetworkingModule.CustomClientBuilder {
            override fun apply(builder: OkHttpClient.Builder) {
                NetworkToolsManager.addInterceptor(builder)
            }
        }
    )
}

After — interceptor only registered in debug builds:

override fun onCreate() {
    super.onCreate()

    if (BuildConfig.DEBUG) {                   // guarded ✅
        NetworkingModule.setCustomClientBuilder(
            object : NetworkingModule.CustomClientBuilder {
                override fun apply(builder: OkHttpClient.Builder) {
                    NetworkToolsManager.addInterceptor(builder)
                }
            }
        )
    }
}

Test plan

• yarn jest plugin/src/index.test.js — all 8 tests pass
• expo prebuild on a fresh Expo app → verify generated MainApplication.kt contains if (BuildConfig.DEBUG)
• eas build --profile production → verify interceptor not active

Related

Depends on #14 (library build.gradle fix) which must be merged first so BuildConfig.DEBUG is reliable.

Closes #15

🤖 Generated with Claude Code